This data sheet presents five families of Vishay Industry Standard Single Channel Phototransistor Couplers. These families include the 4N25/26/27/28 types, the 4N35/36/37/38 couplers, the H11A1/A2/A3/A4/A5, the MCT2/2E, and MCT270/271/272/273/274/275/276/277 devices.Each optocoupler consists of Gallium Arsenide infra- red LED and a silicon NPN phototransistor. These couplers are Underwriters Laboratories (UL) listed to comply with a 5300 V RMS Isolation Test Voltage. This isolation performance is accomplished through Vishay double molding isolation manufac- turing process. Compliance to VDE 0884 partial discharge isolation specification is available for these families by ordering option 1. Phototransistor gain stability, in the presence of high isolation volt- ages, is insured by incorporating a TRansparent lOn Shield (TRIOS) ® on the phototransistor substrate. These isolation pro- cesses and the Vishay IS09001 Quality program results in the high- est isolation performance available for a commercial plastic phototransistor optocoupler. The devices are available in lead formed configuration suitable for surface mounting and are available either on tape and reel, or in standard tube shipping containers.